Photolabile protecting groups, which are also called caging groups, are classes of protecting groups that are particularly useful in the biological sciences. Because light can be controlled with precision both spatially and temporally, cleaving a protecting group from a bioactive molecule allows release, or uncaging, of the molecule. Protecting groups typically mask or conceal charged (for example, carboxylate or phosphate) or polar (for example, amine, hydroxyl, or sulfhydryl) groups on the compounds. Frequently such functionalities increase the hydrophobicity and membrane permeability of the protected molecules. Prior to photolysis, the Photolabile Compounds are typically chemically or biologically inactive because at least one of the compounds' main functionalities is blocked. The activity of the molecule can be triggered by a pulse of light, thereby releasing the molecule from the photoreleasable compound. Thus, photolabile protecting groups can be removed from a protected compound by irradiation, for example, to control the release of the compound when and where desired, either in vivo or in vitro.
Commercially available Photolabile Compounds typically require ultraviolet (UV) light to remove the compounds from the cage. However, UV light can cause damage to organs, tissues and cells, thus making UV light detrimental for in vivo use. Thus, there is a need in the art to utilize new Photolabile Compounds having ligands that can be released using light other than UV light, particularly for in vivo applications. The present invention provides novel Photolabile Compounds and methods for using the compounds, which provide advantages over currently available compounds that are photolabile using only UV light.